Update actions/checkout action to v3

Author: renovate[bot]

.github/workflows/audit.yml

@@ -21,7 +21,7 @@ jobs:
     name: Audit
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: actions-rs/audit-check@v1
         with:
           token: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/build.yml

@@ -13,7 +13,7 @@ jobs:
     name: Lint
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: actions-rs/toolchain@v1
         with:
           profile: minimal
@@ -42,7 +42,7 @@ jobs:
     name: Test
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: actions-rs/toolchain@v1
       - uses: actions-rs/[email protected]
         with:
@@ -67,7 +67,7 @@ jobs:
     name: Build
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: actions-rs/toolchain@v1
       - uses: actions-rs/[email protected]
         with: